presoaking seeds for faster germination?

[habitat-gardener]

This year, I saw pretty poor germination on some tomato seeds we bought for the master gardener sale. All of them were purchased in January and germinated in March. The seeds were densely planted into well-moistened planting mix and then placed onto a heating pad in a commercial greenhouse, covered with plastic until germination started, then the whole container uncovered and moved off the heating mat. Overhead misting kept them moist. After 2 weeks, anything that had germinated, including just-sprouted seeds, was transplanted into 4" pots. The worst germination rate was 48%-54%, three were 64% range, a couple 70%, and the other 27 over 80%. I'd like to move more into the 80%+ bracket and get better germination overall. I wonder how much improvement is possible. Seeds from a couple vendors did poorly. From other vendors, it ranged from so-so to great.

Would it help to soak the seeds overnight? In warm water? Anything added to it? Or any other way to maximize the number of seeds that germinate within 2 weeks? Tell me your experience.

In addition, at home, some of my seeds took 3+ weeks to germinate. No commercial greenhouse here, just shelves and a heat mat in the living room, but they were similarly planted into moistened potting mix and uncovered when germination began. I saw no germination in a couple dozen varieties after a couple weeks, so I double-seeded again, and then discovered that some of the seeds had taken 3 weeks to germinate. This had never happened before! I was used to seeds germinating in 4-5 days unless they were very old. All of some varieties eventually germinated.

[pepperhead212]

That sounds like a temperature problem, since you've had normal, 4 or 5 day germination before. I always soak my tomato seeds overnight, using KNO3 solution, and it does help - something I started using with pepper seeds years ago, which works with tomato and eggplant seeds, as well. A lot of growers just use water, some use hydrogen peroxide - 8 or 9 parts water, to one part 3% H2O2, soaking overnight. I even tried some GA3 with tomato seeds, but it didn't improve their germination (works great for okra, basil, and several others, however).

[habitat-gardener]

That sounds like a temperature problem, since you've had normal, 4 or 5 day germination before. I always soak my tomato seeds overnight, using KNO3 solution, and it does help - something I started using with pepper seeds years ago, which works with tomato and eggplant seeds, as well. A lot of growers just use water, some use hydrogen peroxide - 8 or 9 parts water, to one part 3% H2O2, soaking overnight. I even tried some GA3 with tomato seeds, but it didn't improve their germination (works great for okra, basil, and several others, however).

Thanks! Where do you get the KNO3 solution?

[zeuspaul]

I pre germinate seeds. I soak for a couple of hours in tap water. Then I place the seeds on a small clay block cut from a clay brick (the pic shows my old way with block of wood instead of cut brick). The brick is placed in a glass Pyrex rectangular container filled with water to just below the top of the brick. I place the Pyrex on an electric burner and adjust to about 75°F for tomatoes, 85°F for peppers. At first sign of germination I plant the seed in a starter pot. For peppers I place a ceramic floor tile on the eclectic burner set to low with a grow light above 24-7 set to low until the seed emerges. May or may not do the same with tomatoes depending on temps.

seedstarter.png

seed starter.JPG

[Old chef]

I presoak overnight in a dilute solution of worm tea.
Seams to work nicely for me

Old Chef

[Tormahto]

Mostly using my own saved seeds, no more than 3 years old, "plump" and medium-sized if I have a choice, is how I get my best results. 45% will germinate in 3 days, 45% germinate in 4 days, a very few germinate in 2 days, almost all the rest germinate in 5 - 7 days, with total germination at over 95%.

Estimated temperature is 73 degrees. At 70 degrees, most seeds germinate in 5 - 10 days, instead of the above. I use rain water, or tap water "aired out" for 24 hours. No pre-soaking of seeds, no additives to the water. Results became consistent after staying away from small bags of seed starting mix, and going to a large compressed cube of Pro Mix.

[Kurt]

We always presoak/ inoculation.I keep them wet until the roots show.

IMG_3022.jpeg

A light liquid fert in non city water will give them a good head start.

[pepperhead212]

Thanks! Where do you get the KNO3 solution?

I got a pound of KNO3 about 20 years ago (maybe longer!), probably from Amazon, and use 15 g/pint of water, for the solution.
21 tomato varieties, and one tomatillo, set to soak overnight. by pepperhead212, on Flickr

[MissS]

I don't soak small seeds. I do soak some hard shelled flower seeds though. I plant my tomato seeds in cell packs and keep them at 78 degrees. They will mostly sprout in 3-5 days. Older seed that is not my own, can take 10-15 or more.

[Kurt]

KNO3 is the best fert for us.Potassium Nitrate if used properly,although if mixed with this and that be careful,and it has a long shelf.I gots it in my bloom boost product.Off content ,it was used in the Oklahoma bombing,wiped out stored material in the dockyards over there and will clear stumps as in the old days.Love the stuff.

[Seven Bends]

KNO3 is the best fert for us.Potassium Nitrate if used properly,although if mixed with this and that be careful,and it has a long shelf.I gots it in my bloom boost product.Off content ,it was used in the Oklahoma bombing,wiped out stored material in the dockyards over there and will clear stumps as in the old days.Love the stuff.

Potassium nitrate definitely can be used in explosives and is a component of gunpowder, but it wasn't used in the Oklahoma City bombing. That was ammonium nitrate. Your point about being careful with potassium nitrate is a good one, though.

[zeuspaul]

I have a recollection of Dr. Carolyn recommending a pinch of the blue stuff (MG) for presoaking stubborn seeds.

[Kurt]

Thanx for the clarifications.Keyword Nitrate scares me.

[zeuspaul]

Clara, I don't see any need to look for the equivalents of Miracle Grow and the like. You've got Fish emulsion and that should do well. Just a few drops in water when you soak the seeds. I used new small what we call Dixie cups here, the size that one might find in a despenser in a bathroom.

Zeedman, you're absolutely right that a nitrate soak is good for other seeds as well. The concentration for pure K nitrate is 0.02 %, or maybe 0.2%, can't remember which, which works out to about one teaspoon per gallon of water, which I do remember.

I switched from using pure Knitrate, some know it as saltpetre, many years ago and the products I used above seemed to be a bit better, at least with much older tomato seeds.

Have also tried Giberellic acid, which one has to use with K nitrate or the seedlings are too gangly, as well as cold tea and microwaving.
__________________
Carolyn

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